This application claims the priority of Korean Patent Application No. 2002-81736 filed on Dec. 20, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a semiconductor device, and more particularly, to a simultaneous bi-directional signal transmission system which simultaneously and bi-directionally transmits and receives 4-level signals at high speed, and a simultaneous bi-directional input/output circuit therefor.
2. Description of the Related Art
As the operating speed of a computer system increases, data must be input and output between semiconductor devices at ever-higher speeds. To obtain a higher data rate between semiconductor devices, the semiconductor devices should be connected in point-to-point fashion, i.e., in series, to transmit and receive data. This is normally referred to as “serial communication.”
However, serial communication suffers from impedance mismatching between semiconductor devices, interference between transmission signals, distance of serial communication, and data skew.